Imprecision in the ratio between the true value of the frequency of a clock of a radio communication terminal and the carrier frequency of the signals it receives is problematic. The terminal must synchronize precisely with the frequency of the electromagnetic waves used to carry communication signals on the radio communications network.
An offset can have various causes. For example, temperature variations in the circuits or aging of components (such as the quartz in the oscillators) may cause such an offset.
It is desirable to estimate this offset so it can be corrected to ensure good communication quality.